Add latency checks to peer connection and status output (#1725)

* adding peer healthcheck

* generate proto file

* fix return in udp mux and replace with continue

* use ice agent for latency checks

* fix status output

* remove some logs

* fix status test

* revert bind and ebpf code

* fix error handling on binding response callback

* extend error handling on binding response callback

---------

Co-authored-by: Maycon Santos <mlsmaycon@gmail.com>

client/internal/peer/conn.go

@@ -133,6 +133,9 @@ type Conn struct {
 	adapter        iface.TunAdapter
 	iFaceDiscover  stdnet.ExternalIFaceDiscover
 	sentExtraSrflx bool
+
+	remoteEndpoint *net.UDPAddr
+	remoteConn     *ice.Conn
 }
 
 // meta holds meta information about a connection
@@ -234,6 +237,17 @@ func (conn *Conn) reCreateAgent() error {
 		return err
 	}
 
+	err = conn.agent.OnSuccessfulSelectedPairBindingResponse(func(p *ice.CandidatePair) {
+		err := conn.statusRecorder.UpdateLatency(conn.config.Key, p.Latency())
+		if err != nil {
+			log.Debugf("failed to update latency for peer %s: %s", conn.config.Key, err)
+			return
+		}
+	})
+	if err != nil {
+		return fmt.Errorf("failed setting binding response callback: %w", err)
+	}
+
 	return nil
 }
 
@@ -348,6 +362,9 @@ func (conn *Conn) Open() error {
 	if remoteOfferAnswer.WgListenPort != 0 {
 		remoteWgPort = remoteOfferAnswer.WgListenPort
 	}
+
+	conn.remoteConn = remoteConn
+
 	// the ice connection has been established successfully so we are ready to start the proxy
 	remoteAddr, err := conn.configureConnection(remoteConn, remoteWgPort, remoteOfferAnswer.RosenpassPubKey,
 		remoteOfferAnswer.RosenpassAddr)
@@ -397,6 +414,7 @@ func (conn *Conn) configureConnection(remoteConn net.Conn, remoteWgPort int, rem
 	}
 
 	endpointUdpAddr, _ := net.ResolveUDPAddr(endpoint.Network(), endpoint.String())
+	conn.remoteEndpoint = endpointUdpAddr
 
 	err = conn.config.WgConfig.WgInterface.UpdatePeer(conn.config.WgConfig.RemoteKey, conn.config.WgConfig.AllowedIps, defaultWgKeepAlive, endpointUdpAddr, conn.config.WgConfig.PreSharedKey)
 	if err != nil {

client/internal/peer/status.go

@@ -28,6 +28,7 @@ type State struct {
 	LastWireguardHandshake     time.Time
 	BytesTx                    int64
 	BytesRx                    int64
+	Latency                    time.Duration
 	RosenpassEnabled           bool
 	Routes                     map[string]struct{}
 }
@@ -410,6 +411,22 @@ func (d *Status) GetManagementState() ManagementState {
 	}
 }
 
+func (d *Status) UpdateLatency(pubKey string, latency time.Duration) error {
+	if latency <= 0 {
+		return nil
+	}
+
+	d.mux.Lock()
+	defer d.mux.Unlock()
+	peerState, ok := d.peers[pubKey]
+	if !ok {
+		return errors.New("peer doesn't exist")
+	}
+	peerState.Latency = latency
+	d.peers[pubKey] = peerState
+	return nil
+}
+
 // IsLoginRequired determines if a peer's login has expired.
 func (d *Status) IsLoginRequired() bool {
 	d.mux.Lock()